Suspended Pavement Systems

• A suspended pavement system allows the pavement to rest on a series of pillars, instead of compacting the soil. Tree roots can continue to grow in this system, which increases their water filtration abilities. US Environmental Protection Agency (2013). Stormwater to street trees: Section 3, Stormwater management systems with trees. p.12-23.

Silva CellsNew York State Nursery and Landscape Association

Structural Soils

• Soil and gravel mixes that act as a base for pavement, called structural soil, consist of 70% to 80% gravel, and 20% to 30% soil that holds stormwater and allows roots to grow, while still meeting the load-bearing requirements to support roadways.US Environmental Protection Agency (2013). Stormwater to street trees: Section 3, Stormwater management systems with trees. p.12-23.

Stormwater Tree Pits

• Stormwater tree pits are modified tree pits with more growing area than a traditional pit. Connecting multiple tree pits maximizes the ability for the reservoirs to hold water and the trees to filter the runoff. US Environmental Protection Agency (2013). Stormwater to street trees: Section 3, Stormwater management systems with trees. p.12-23.

TreeswaleDesign-a-Landscape, Tumblr

Permeable Pavements

• A wide variety of permeable pavements, from concretes to paver systems, allow water to filter through to the tree roots below, and reduces runoff. US Environmental Protection Agency (2013). Stormwater to street trees: Section 3, Stormwater management systems with trees. p.12-23.

Flexi-Pavekbius.com

Bioswales

• Forested bioswales feature a graded depression surrounded by trees and other vegetation that filter stormwater before it is channeled into a stormwater drain. US Environmental Protection Agency (2013). Stormwater to street trees: Section 3, Stormwater management systems with trees. p.12-23.

Bioswale in Washington, DCCredit: Dan Reed